This invention is related to telephone line usage and subscriber cost reductions
At the time of the present invention, fax, telecopier or telefacsimile machines have become popular. Their popularity and sales and competition in their manufacture have reduced retail cost of the machines to about $800.00. Business telephone lines are billed at about $20.00 a month. Over the life of a fax machine, basic telephone line availability charges exceed the cost of the fax machine "Fax", "telefax", "facsimile" and "telecopier" are used interchangeably.
At the time of this invention local telephone companies have begun offering add-on features to existing or new lines which allow the subscriber, in the words of the telephone company, to determine whom a call is from or for before answering the telephone. The service, called IdentaRing by Bell Operating Companies, but may be called other things by other telephone companies, is much like an individual party line service In the present implementation, up to three numbers are assigned to one line. When a caller calls the first number a long ringing signal is made. When a party calls the second number, a short, short ringing signal is made. A call of the third number produces a short, long, short ringing signal. Different patterns may be used with expanded services or in other areas. In fact, the new IdentaRing service operates much as an individual inbound party line. Out calls are all made on a single number. Further information about the service is currently available by calling 1-800-678-RING or asking a local office for an IdentaRing brochure.
U.S. Pat. No. 4,146,754 uses the timing of ringing signals to select different devices or telephones. This requires two separate telephone calls That disclosure would not be operative with the IdentaRing service. The elements are used in a distinct way.
Apparatus for selectively alerting party line subscribers has been described in U.S. Pat. No. 4,723,271, which relies on changing the nature of the ringing signal and identifying the different nature of the signals That patent involves voltage and polarity as opposed to timing, and would require special hardware at the central office.
Local telephone companies in urban areas avoid use of the "party line" concept and have been discontinuing existing party line service. In fact, many historic party line subscribers have individual lines, other parties on the lines having been converted to individual service.
A problem exists for telephone subscribers in how to obtain maximum use of telephone lines and minimize office overhead and communication expenses. This invention proposes one solution to the continuing problems.